Life history . Detailed information on the reproductive cycle of the 

 bloodworm generally is scarce. Like most polychaetes, this species has two 

 sexes. Sexual maturity is reached probably in the 3rd year, and the rate of 

 maturation appears to be dependent upon both temperature and the physiological 

 condition of the organism (Simpson 1962). 



The bloodworm spawns primarily in June in Maine; however, rare occurrences of 

 winter spawning have also been observed (Creaser 1973). Few spawners have 

 been found in Maine east of Frenchman Bay (Skillings and Taunton Rivers; 

 region 5; personal communication from E. P. Creaser, Maine Department of 

 Marine Resources, Augusta, ME; November, 1977). Adult populations in eastern 

 Maine may be recruited from distant populations by larval dispersal. 



The formation of eggs and sperm begins in the fall and by March the females 

 are swollen with eggs (Creaser 1973) . The number of eggs per individual 

 varies from about 3 million to almost 10 million depending on the size of the 

 individual. The species undergoes limited epitoky prior to spawning, a 

 phenomenon typical of certain polychaetes, in which the worm's body becomes 

 structurally modified. The body wall becomes thin and fragile and the skin 

 changes in pigmentation. Males and females may be distinguished just prior to 

 spawning by color differences. Males are light cream in color and females are 

 brown (Creaser 1973; and Klawe and Dickie 1957). 



Spawning bloodworms leave their burrows and swim to the surface in swarms to 

 release their gametes. What controls the timing of swarming is not known, 

 though temperature at the place of spawning, tidal amplitude, and hormonal 

 factors may affect it. A minimum water temperature of 55 F (13 C) for 

 spawning in Maine was reported by Creaser (1973). In a study conducted in the 

 Montsweag Bay-Wiscasset area, populations of bloodworms near the Maine Yankee 

 nuclear power plant spawned earlier than control populations (Mazurkiewicz and 

 Scott 1973), presumably because of the warmer water near the plant. Both 

 Simpson (1962) and Creaser (1973) observed swarming just prior to and during 

 the second high tide of the day. It is not known if the presence of both 

 sexes is required for the release of gametes during swarming. Gametes are 

 emitted as a result of the muscular contraction in swimming. 



After gametes have been shed the adult is spent, and its body collapses and 

 sinks to the bottom (Creaser 1973; and Klawe and Dickie 1957). Although 

 Creaser (1973) concludes that all bloodworms die after spawning, Simpson 

 (1962) believes that some spawners may survive. 



The fertilized eggs apparently settle to the bottom, develop to the larval 

 stage, and become pelagic for a short time. Mazurkiewicz (1974) found that 

 during intense periods of spawning activity numerous bloodworm larvae were 

 present in the plankton. These and later larval stages were observed in the 

 plankton for only a short period after spawning (Mazurkiewicz 1974) . The 

 apparent disappearance of larvae from the plankton is unexplained, but they 

 may leave the water column and live on the surface of the bottom. No 

 information is available about the length of the larval stage. 



Adult bloodworms feed primarily on detritus (Klawe and Dickie 1957; and 

 Pettibone 1963) and are especially abundant in areas rich in detritus (Dean 

 and Ewart 1978). Other food items include polychaetes (including other 



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